Association of ticagrelor versus clopidogrel with in-hospital early outcomes in elderly patients with acute myocardial infarction complicated by cardiogenic shock: findings from CCC-ACS project

Background: Elderly patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) have a markedly high mortality. Although ticagrelor has demonstrated superiority over clopidogrel in the AMI population, its efficacy and safety in elderly patients with AMI-CS remain uncertain. This study aimed to compare the associations of ticagrelor and clopidogrel with early in-hospital clinical outcomes in elderly patients with AMI-CS. Methods: This retrospective study included 839 patients aged ≥65 years with AMI-CS who underwent percutaneous coronary intervention (PCI) at participating hospitals in China within the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome (CCC-ACS) project between November 2014 and December 2020. Patients with missing information on dual antiplatelet therapy (DAPT), those who did not receive DAPT within 24 hours of first medical contact, and those with combined use of or switching between P2Y12 inhibitors during hospitalization were excluded. Patients were grouped according to the P2Y12 inhibitor received: ticagrelor (n=314) or clopidogrel (n=525). The primary outcomes were all-cause mortality and major bleeding during the first 15 days of hospitalization; major adverse cardiovascular events (MACE) were a secondary outcome. Multivariable Cox regression, propensity score matching (PSM), and inverse probability of treatment weighting (IPTW) were used to adjust for potential confounders. Results: Compared with clopidogrel, ticagrelor was associated with higher risk of all-cause mortality [adjusted hazard ratio (HR) 1.52, 95% confidence interval (CI): 1.05–2.21, P=0.03] and MACE (adjusted HR 1.48, 95% CI: 1.09–2.01, P=0.01) during the first 15 days of hospitalization, without a statistically significant difference in major bleeding (adjusted HR 1.76, 95% CI: 0.68–4.52, P=0.24). Subgroup analyses generally showed a similar direction of association for all-cause mortality. The associations with mortality and MACE remained statistically significant after PSM; the corresponding IPTW estimates were directionally similar but not statistically significant. Conclusions: Among elderly AMI-CS patients undergoing PCI, ticagrelor did not confer a clinical benefit over clopidogrel and was associated with increased in-hospital mortality and MACE without a significant increase in major bleeding. These findings highlight the need for cautious selection of P2Y12 inhibitors in this high-risk population and further prospective studies to guide individualized therapy.